1 //===-- sanitizer_linux.cpp -----------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is shared between AddressSanitizer and ThreadSanitizer 10 // run-time libraries and implements linux-specific functions from 11 // sanitizer_libc.h. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_platform.h" 15 16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 17 SANITIZER_OPENBSD || SANITIZER_SOLARIS 18 19 #include "sanitizer_common.h" 20 #include "sanitizer_flags.h" 21 #include "sanitizer_getauxval.h" 22 #include "sanitizer_internal_defs.h" 23 #include "sanitizer_libc.h" 24 #include "sanitizer_linux.h" 25 #include "sanitizer_mutex.h" 26 #include "sanitizer_placement_new.h" 27 #include "sanitizer_procmaps.h" 28 29 #if SANITIZER_LINUX && !SANITIZER_GO 30 #include <asm/param.h> 31 #endif 32 33 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat' 34 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To 35 // access stat from asm/stat.h, without conflicting with definition in 36 // sys/stat.h, we use this trick. 37 #if defined(__mips64) 38 #include <asm/unistd.h> 39 #include <sys/types.h> 40 #define stat kernel_stat 41 #include <asm/stat.h> 42 #undef stat 43 #endif 44 45 #include <dlfcn.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <link.h> 49 #include <pthread.h> 50 #include <sched.h> 51 #include <signal.h> 52 #include <sys/mman.h> 53 #include <sys/param.h> 54 #if !SANITIZER_SOLARIS 55 #include <sys/ptrace.h> 56 #endif 57 #include <sys/resource.h> 58 #include <sys/stat.h> 59 #include <sys/syscall.h> 60 #include <sys/time.h> 61 #include <sys/types.h> 62 #if !SANITIZER_OPENBSD 63 #include <ucontext.h> 64 #endif 65 #if SANITIZER_OPENBSD 66 #include <sys/futex.h> 67 #include <sys/sysctl.h> 68 #endif 69 #include <unistd.h> 70 71 #if SANITIZER_LINUX 72 #include <sys/utsname.h> 73 #endif 74 75 #if SANITIZER_LINUX && !SANITIZER_ANDROID 76 #include <sys/personality.h> 77 #endif 78 79 #if SANITIZER_FREEBSD 80 #include <sys/exec.h> 81 #include <sys/sysctl.h> 82 #include <machine/atomic.h> 83 extern "C" { 84 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on 85 // FreeBSD 9.2 and 10.0. 86 #include <sys/umtx.h> 87 } 88 #include <sys/thr.h> 89 #endif // SANITIZER_FREEBSD 90 91 #if SANITIZER_NETBSD 92 #include <limits.h> // For NAME_MAX 93 #include <sys/sysctl.h> 94 #include <sys/exec.h> 95 extern struct ps_strings *__ps_strings; 96 #endif // SANITIZER_NETBSD 97 98 #if SANITIZER_SOLARIS 99 #include <stdlib.h> 100 #include <thread.h> 101 #define environ _environ 102 #endif 103 104 extern char **environ; 105 106 #if SANITIZER_LINUX 107 // <linux/time.h> 108 struct kernel_timeval { 109 long tv_sec; 110 long tv_usec; 111 }; 112 113 // <linux/futex.h> is broken on some linux distributions. 114 const int FUTEX_WAIT = 0; 115 const int FUTEX_WAKE = 1; 116 const int FUTEX_PRIVATE_FLAG = 128; 117 const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG; 118 const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG; 119 #endif // SANITIZER_LINUX 120 121 // Are we using 32-bit or 64-bit Linux syscalls? 122 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32 123 // but it still needs to use 64-bit syscalls. 124 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \ 125 SANITIZER_WORDSIZE == 64) 126 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1 127 #else 128 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0 129 #endif 130 131 // Note : FreeBSD had implemented both 132 // Linux and OpenBSD apis, available from 133 // future 12.x version most likely 134 #if SANITIZER_LINUX && defined(__NR_getrandom) 135 # if !defined(GRND_NONBLOCK) 136 # define GRND_NONBLOCK 1 137 # endif 138 # define SANITIZER_USE_GETRANDOM 1 139 #else 140 # define SANITIZER_USE_GETRANDOM 0 141 #endif // SANITIZER_LINUX && defined(__NR_getrandom) 142 143 #if SANITIZER_OPENBSD 144 # define SANITIZER_USE_GETENTROPY 1 145 #else 146 # if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000 147 # define SANITIZER_USE_GETENTROPY 1 148 # else 149 # define SANITIZER_USE_GETENTROPY 0 150 # endif 151 #endif // SANITIZER_USE_GETENTROPY 152 153 namespace __sanitizer { 154 155 #if SANITIZER_LINUX && defined(__x86_64__) 156 #include "sanitizer_syscall_linux_x86_64.inc" 157 #elif SANITIZER_LINUX && SANITIZER_RISCV64 158 #include "sanitizer_syscall_linux_riscv64.inc" 159 #elif SANITIZER_LINUX && defined(__aarch64__) 160 #include "sanitizer_syscall_linux_aarch64.inc" 161 #elif SANITIZER_LINUX && defined(__arm__) 162 #include "sanitizer_syscall_linux_arm.inc" 163 #else 164 #include "sanitizer_syscall_generic.inc" 165 #endif 166 167 // --------------- sanitizer_libc.h 168 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD 169 #if !SANITIZER_S390 && !SANITIZER_OPENBSD 170 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd, 171 u64 offset) { 172 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS 173 return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd, 174 offset); 175 #else 176 // mmap2 specifies file offset in 4096-byte units. 177 CHECK(IsAligned(offset, 4096)); 178 return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd, 179 offset / 4096); 180 #endif 181 } 182 #endif // !SANITIZER_S390 && !SANITIZER_OPENBSD 183 184 #if !SANITIZER_OPENBSD 185 uptr internal_munmap(void *addr, uptr length) { 186 return internal_syscall(SYSCALL(munmap), (uptr)addr, length); 187 } 188 189 int internal_mprotect(void *addr, uptr length, int prot) { 190 return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot); 191 } 192 193 int internal_madvise(uptr addr, uptr length, int advice) { 194 return internal_syscall(SYSCALL(madvise), addr, length, advice); 195 } 196 #endif 197 198 uptr internal_close(fd_t fd) { 199 return internal_syscall(SYSCALL(close), fd); 200 } 201 202 uptr internal_open(const char *filename, int flags) { 203 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 204 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags); 205 #else 206 return internal_syscall(SYSCALL(open), (uptr)filename, flags); 207 #endif 208 } 209 210 uptr internal_open(const char *filename, int flags, u32 mode) { 211 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 212 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags, 213 mode); 214 #else 215 return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode); 216 #endif 217 } 218 219 uptr internal_read(fd_t fd, void *buf, uptr count) { 220 sptr res; 221 HANDLE_EINTR(res, 222 (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count)); 223 return res; 224 } 225 226 uptr internal_write(fd_t fd, const void *buf, uptr count) { 227 sptr res; 228 HANDLE_EINTR(res, 229 (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count)); 230 return res; 231 } 232 233 uptr internal_ftruncate(fd_t fd, uptr size) { 234 sptr res; 235 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd, 236 (OFF_T)size)); 237 return res; 238 } 239 240 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX 241 static void stat64_to_stat(struct stat64 *in, struct stat *out) { 242 internal_memset(out, 0, sizeof(*out)); 243 out->st_dev = in->st_dev; 244 out->st_ino = in->st_ino; 245 out->st_mode = in->st_mode; 246 out->st_nlink = in->st_nlink; 247 out->st_uid = in->st_uid; 248 out->st_gid = in->st_gid; 249 out->st_rdev = in->st_rdev; 250 out->st_size = in->st_size; 251 out->st_blksize = in->st_blksize; 252 out->st_blocks = in->st_blocks; 253 out->st_atime = in->st_atime; 254 out->st_mtime = in->st_mtime; 255 out->st_ctime = in->st_ctime; 256 } 257 #endif 258 259 #if defined(__mips64) 260 // Undefine compatibility macros from <sys/stat.h> 261 // so that they would not clash with the kernel_stat 262 // st_[a|m|c]time fields 263 #undef st_atime 264 #undef st_mtime 265 #undef st_ctime 266 #if defined(SANITIZER_ANDROID) 267 // Bionic sys/stat.h defines additional macros 268 // for compatibility with the old NDKs and 269 // they clash with the kernel_stat structure 270 // st_[a|m|c]time_nsec fields. 271 #undef st_atime_nsec 272 #undef st_mtime_nsec 273 #undef st_ctime_nsec 274 #endif 275 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) { 276 internal_memset(out, 0, sizeof(*out)); 277 out->st_dev = in->st_dev; 278 out->st_ino = in->st_ino; 279 out->st_mode = in->st_mode; 280 out->st_nlink = in->st_nlink; 281 out->st_uid = in->st_uid; 282 out->st_gid = in->st_gid; 283 out->st_rdev = in->st_rdev; 284 out->st_size = in->st_size; 285 out->st_blksize = in->st_blksize; 286 out->st_blocks = in->st_blocks; 287 #if defined(__USE_MISC) || \ 288 defined(__USE_XOPEN2K8) || \ 289 defined(SANITIZER_ANDROID) 290 out->st_atim.tv_sec = in->st_atime; 291 out->st_atim.tv_nsec = in->st_atime_nsec; 292 out->st_mtim.tv_sec = in->st_mtime; 293 out->st_mtim.tv_nsec = in->st_mtime_nsec; 294 out->st_ctim.tv_sec = in->st_ctime; 295 out->st_ctim.tv_nsec = in->st_ctime_nsec; 296 #else 297 out->st_atime = in->st_atime; 298 out->st_atimensec = in->st_atime_nsec; 299 out->st_mtime = in->st_mtime; 300 out->st_mtimensec = in->st_mtime_nsec; 301 out->st_ctime = in->st_ctime; 302 out->st_atimensec = in->st_ctime_nsec; 303 #endif 304 } 305 #endif 306 307 uptr internal_stat(const char *path, void *buf) { 308 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD 309 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0); 310 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 311 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, 312 0); 313 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS 314 # if defined(__mips64) 315 // For mips64, stat syscall fills buffer in the format of kernel_stat 316 struct kernel_stat kbuf; 317 int res = internal_syscall(SYSCALL(stat), path, &kbuf); 318 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 319 return res; 320 # else 321 return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf); 322 # endif 323 #else 324 struct stat64 buf64; 325 int res = internal_syscall(SYSCALL(stat64), path, &buf64); 326 stat64_to_stat(&buf64, (struct stat *)buf); 327 return res; 328 #endif 329 } 330 331 uptr internal_lstat(const char *path, void *buf) { 332 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD 333 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 334 AT_SYMLINK_NOFOLLOW); 335 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 336 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, 337 AT_SYMLINK_NOFOLLOW); 338 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS 339 # if SANITIZER_MIPS64 340 // For mips64, lstat syscall fills buffer in the format of kernel_stat 341 struct kernel_stat kbuf; 342 int res = internal_syscall(SYSCALL(lstat), path, &kbuf); 343 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 344 return res; 345 # else 346 return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf); 347 # endif 348 #else 349 struct stat64 buf64; 350 int res = internal_syscall(SYSCALL(lstat64), path, &buf64); 351 stat64_to_stat(&buf64, (struct stat *)buf); 352 return res; 353 #endif 354 } 355 356 uptr internal_fstat(fd_t fd, void *buf) { 357 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD || \ 358 SANITIZER_LINUX_USES_64BIT_SYSCALLS 359 #if SANITIZER_MIPS64 && !SANITIZER_OPENBSD 360 // For mips64, fstat syscall fills buffer in the format of kernel_stat 361 struct kernel_stat kbuf; 362 int res = internal_syscall(SYSCALL(fstat), fd, &kbuf); 363 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 364 return res; 365 # else 366 return internal_syscall(SYSCALL(fstat), fd, (uptr)buf); 367 # endif 368 #else 369 struct stat64 buf64; 370 int res = internal_syscall(SYSCALL(fstat64), fd, &buf64); 371 stat64_to_stat(&buf64, (struct stat *)buf); 372 return res; 373 #endif 374 } 375 376 uptr internal_filesize(fd_t fd) { 377 struct stat st; 378 if (internal_fstat(fd, &st)) 379 return -1; 380 return (uptr)st.st_size; 381 } 382 383 uptr internal_dup(int oldfd) { 384 return internal_syscall(SYSCALL(dup), oldfd); 385 } 386 387 uptr internal_dup2(int oldfd, int newfd) { 388 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 389 return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0); 390 #else 391 return internal_syscall(SYSCALL(dup2), oldfd, newfd); 392 #endif 393 } 394 395 uptr internal_readlink(const char *path, char *buf, uptr bufsize) { 396 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 397 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf, 398 bufsize); 399 #elif SANITIZER_OPENBSD 400 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf, 401 bufsize); 402 #else 403 return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize); 404 #endif 405 } 406 407 uptr internal_unlink(const char *path) { 408 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD 409 return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0); 410 #else 411 return internal_syscall(SYSCALL(unlink), (uptr)path); 412 #endif 413 } 414 415 uptr internal_rename(const char *oldpath, const char *newpath) { 416 #if defined(__riscv) 417 return internal_syscall(SYSCALL(renameat2), AT_FDCWD, (uptr)oldpath, AT_FDCWD, 418 (uptr)newpath, 0); 419 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD 420 return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD, 421 (uptr)newpath); 422 #else 423 return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath); 424 #endif 425 } 426 427 uptr internal_sched_yield() { 428 return internal_syscall(SYSCALL(sched_yield)); 429 } 430 431 unsigned int internal_sleep(unsigned int seconds) { 432 struct timespec ts; 433 ts.tv_sec = seconds; 434 ts.tv_nsec = 0; 435 int res = internal_syscall(SYSCALL(nanosleep), &ts, &ts); 436 if (res) return ts.tv_sec; 437 return 0; 438 } 439 440 uptr internal_execve(const char *filename, char *const argv[], 441 char *const envp[]) { 442 return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv, 443 (uptr)envp); 444 } 445 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD 446 447 #if !SANITIZER_NETBSD 448 void internal__exit(int exitcode) { 449 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD || SANITIZER_SOLARIS 450 internal_syscall(SYSCALL(exit), exitcode); 451 #else 452 internal_syscall(SYSCALL(exit_group), exitcode); 453 #endif 454 Die(); // Unreachable. 455 } 456 #endif // !SANITIZER_NETBSD 457 458 // ----------------- sanitizer_common.h 459 bool FileExists(const char *filename) { 460 if (ShouldMockFailureToOpen(filename)) 461 return false; 462 struct stat st; 463 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 464 if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0)) 465 #else 466 if (internal_stat(filename, &st)) 467 #endif 468 return false; 469 // Sanity check: filename is a regular file. 470 return S_ISREG(st.st_mode); 471 } 472 473 #if !SANITIZER_NETBSD 474 tid_t GetTid() { 475 #if SANITIZER_FREEBSD 476 long Tid; 477 thr_self(&Tid); 478 return Tid; 479 #elif SANITIZER_OPENBSD 480 return internal_syscall(SYSCALL(getthrid)); 481 #elif SANITIZER_SOLARIS 482 return thr_self(); 483 #else 484 return internal_syscall(SYSCALL(gettid)); 485 #endif 486 } 487 488 int TgKill(pid_t pid, tid_t tid, int sig) { 489 #if SANITIZER_LINUX 490 return internal_syscall(SYSCALL(tgkill), pid, tid, sig); 491 #elif SANITIZER_FREEBSD 492 return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig); 493 #elif SANITIZER_OPENBSD 494 (void)pid; 495 return internal_syscall(SYSCALL(thrkill), tid, sig, nullptr); 496 #elif SANITIZER_SOLARIS 497 (void)pid; 498 return thr_kill(tid, sig); 499 #endif 500 } 501 #endif 502 503 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD 504 u64 NanoTime() { 505 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD 506 timeval tv; 507 #else 508 kernel_timeval tv; 509 #endif 510 internal_memset(&tv, 0, sizeof(tv)); 511 internal_syscall(SYSCALL(gettimeofday), &tv, 0); 512 return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000; 513 } 514 515 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) { 516 return internal_syscall(SYSCALL(clock_gettime), clk_id, tp); 517 } 518 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD 519 520 // Like getenv, but reads env directly from /proc (on Linux) or parses the 521 // 'environ' array (on some others) and does not use libc. This function 522 // should be called first inside __asan_init. 523 const char *GetEnv(const char *name) { 524 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD || \ 525 SANITIZER_SOLARIS 526 if (::environ != 0) { 527 uptr NameLen = internal_strlen(name); 528 for (char **Env = ::environ; *Env != 0; Env++) { 529 if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=') 530 return (*Env) + NameLen + 1; 531 } 532 } 533 return 0; // Not found. 534 #elif SANITIZER_LINUX 535 static char *environ; 536 static uptr len; 537 static bool inited; 538 if (!inited) { 539 inited = true; 540 uptr environ_size; 541 if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len)) 542 environ = nullptr; 543 } 544 if (!environ || len == 0) return nullptr; 545 uptr namelen = internal_strlen(name); 546 const char *p = environ; 547 while (*p != '\0') { // will happen at the \0\0 that terminates the buffer 548 // proc file has the format NAME=value\0NAME=value\0NAME=value\0... 549 const char* endp = 550 (char*)internal_memchr(p, '\0', len - (p - environ)); 551 if (!endp) // this entry isn't NUL terminated 552 return nullptr; 553 else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match. 554 return p + namelen + 1; // point after = 555 p = endp + 1; 556 } 557 return nullptr; // Not found. 558 #else 559 #error "Unsupported platform" 560 #endif 561 } 562 563 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_OPENBSD && \ 564 !SANITIZER_GO 565 extern "C" { 566 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end; 567 } 568 #endif 569 570 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && \ 571 !SANITIZER_OPENBSD 572 static void ReadNullSepFileToArray(const char *path, char ***arr, 573 int arr_size) { 574 char *buff; 575 uptr buff_size; 576 uptr buff_len; 577 *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray"); 578 if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) { 579 (*arr)[0] = nullptr; 580 return; 581 } 582 (*arr)[0] = buff; 583 int count, i; 584 for (count = 1, i = 1; ; i++) { 585 if (buff[i] == 0) { 586 if (buff[i+1] == 0) break; 587 (*arr)[count] = &buff[i+1]; 588 CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible. 589 count++; 590 } 591 } 592 (*arr)[count] = nullptr; 593 } 594 #endif 595 596 #if !SANITIZER_OPENBSD 597 static void GetArgsAndEnv(char ***argv, char ***envp) { 598 #if SANITIZER_FREEBSD 599 // On FreeBSD, retrieving the argument and environment arrays is done via the 600 // kern.ps_strings sysctl, which returns a pointer to a structure containing 601 // this information. See also <sys/exec.h>. 602 ps_strings *pss; 603 uptr sz = sizeof(pss); 604 if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) { 605 Printf("sysctl kern.ps_strings failed\n"); 606 Die(); 607 } 608 *argv = pss->ps_argvstr; 609 *envp = pss->ps_envstr; 610 #elif SANITIZER_NETBSD 611 *argv = __ps_strings->ps_argvstr; 612 *envp = __ps_strings->ps_envstr; 613 #else // SANITIZER_FREEBSD 614 #if !SANITIZER_GO 615 if (&__libc_stack_end) { 616 uptr* stack_end = (uptr*)__libc_stack_end; 617 // Normally argc can be obtained from *stack_end, however, on ARM glibc's 618 // _start clobbers it: 619 // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/arm/start.S;hb=refs/heads/release/2.31/master#l75 620 // Do not special-case ARM and infer argc from argv everywhere. 621 int argc = 0; 622 while (stack_end[argc + 1]) argc++; 623 *argv = (char**)(stack_end + 1); 624 *envp = (char**)(stack_end + argc + 2); 625 } else { 626 #endif // !SANITIZER_GO 627 static const int kMaxArgv = 2000, kMaxEnvp = 2000; 628 ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv); 629 ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp); 630 #if !SANITIZER_GO 631 } 632 #endif // !SANITIZER_GO 633 #endif // SANITIZER_FREEBSD 634 } 635 636 char **GetArgv() { 637 char **argv, **envp; 638 GetArgsAndEnv(&argv, &envp); 639 return argv; 640 } 641 642 char **GetEnviron() { 643 char **argv, **envp; 644 GetArgsAndEnv(&argv, &envp); 645 return envp; 646 } 647 648 #endif // !SANITIZER_OPENBSD 649 650 #if !SANITIZER_SOLARIS 651 enum MutexState { 652 MtxUnlocked = 0, 653 MtxLocked = 1, 654 MtxSleeping = 2 655 }; 656 657 BlockingMutex::BlockingMutex() { 658 internal_memset(this, 0, sizeof(*this)); 659 } 660 661 void BlockingMutex::Lock() { 662 CHECK_EQ(owner_, 0); 663 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_); 664 if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked) 665 return; 666 while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) { 667 #if SANITIZER_FREEBSD 668 _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0); 669 #elif SANITIZER_NETBSD 670 sched_yield(); /* No userspace futex-like synchronization */ 671 #else 672 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT_PRIVATE, MtxSleeping, 673 0, 0, 0); 674 #endif 675 } 676 } 677 678 void BlockingMutex::Unlock() { 679 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_); 680 u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release); 681 CHECK_NE(v, MtxUnlocked); 682 if (v == MtxSleeping) { 683 #if SANITIZER_FREEBSD 684 _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0); 685 #elif SANITIZER_NETBSD 686 /* No userspace futex-like synchronization */ 687 #else 688 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE_PRIVATE, 1, 0, 0, 0); 689 #endif 690 } 691 } 692 693 void BlockingMutex::CheckLocked() { 694 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_); 695 CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed)); 696 } 697 #endif // !SANITIZER_SOLARIS 698 699 // ----------------- sanitizer_linux.h 700 // The actual size of this structure is specified by d_reclen. 701 // Note that getdents64 uses a different structure format. We only provide the 702 // 32-bit syscall here. 703 #if SANITIZER_NETBSD 704 // Not used 705 #elif SANITIZER_OPENBSD 706 // struct dirent is different for Linux and us. At this moment, we use only 707 // d_fileno (Linux call this d_ino), d_reclen, and d_name. 708 struct linux_dirent { 709 u64 d_ino; // d_fileno 710 u16 d_reclen; 711 u16 d_namlen; // not used 712 u8 d_type; // not used 713 char d_name[NAME_MAX + 1]; 714 }; 715 #else 716 struct linux_dirent { 717 #if SANITIZER_X32 || defined(__aarch64__) || SANITIZER_RISCV64 718 u64 d_ino; 719 u64 d_off; 720 #else 721 unsigned long d_ino; 722 unsigned long d_off; 723 #endif 724 unsigned short d_reclen; 725 #if defined(__aarch64__) || SANITIZER_RISCV64 726 unsigned char d_type; 727 #endif 728 char d_name[256]; 729 }; 730 #endif 731 732 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD 733 // Syscall wrappers. 734 uptr internal_ptrace(int request, int pid, void *addr, void *data) { 735 return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr, 736 (uptr)data); 737 } 738 739 uptr internal_waitpid(int pid, int *status, int options) { 740 return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options, 741 0 /* rusage */); 742 } 743 744 uptr internal_getpid() { 745 return internal_syscall(SYSCALL(getpid)); 746 } 747 748 uptr internal_getppid() { 749 return internal_syscall(SYSCALL(getppid)); 750 } 751 752 int internal_dlinfo(void *handle, int request, void *p) { 753 #if SANITIZER_FREEBSD 754 return dlinfo(handle, request, p); 755 #else 756 UNIMPLEMENTED(); 757 #endif 758 } 759 760 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) { 761 #if SANITIZER_FREEBSD 762 return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL); 763 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 764 return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count); 765 #else 766 return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count); 767 #endif 768 } 769 770 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) { 771 return internal_syscall(SYSCALL(lseek), fd, offset, whence); 772 } 773 774 #if SANITIZER_LINUX 775 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) { 776 return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5); 777 } 778 #endif 779 780 uptr internal_sigaltstack(const void *ss, void *oss) { 781 return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss); 782 } 783 784 int internal_fork() { 785 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 786 return internal_syscall(SYSCALL(clone), SIGCHLD, 0); 787 #else 788 return internal_syscall(SYSCALL(fork)); 789 #endif 790 } 791 792 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD 793 int internal_sysctl(const int *name, unsigned int namelen, void *oldp, 794 uptr *oldlenp, const void *newp, uptr newlen) { 795 #if SANITIZER_OPENBSD 796 return sysctl(name, namelen, oldp, (size_t *)oldlenp, (void *)newp, 797 (size_t)newlen); 798 #else 799 return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp, 800 (size_t *)oldlenp, newp, (size_t)newlen); 801 #endif 802 } 803 804 #if SANITIZER_FREEBSD 805 int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp, 806 const void *newp, uptr newlen) { 807 // Note: this function can be called during startup, so we need to avoid 808 // calling any interceptable functions. On FreeBSD >= 1300045 sysctlbyname() 809 // is a real syscall, but for older versions it calls sysctlnametomib() 810 // followed by sysctl(). To avoid calling the intercepted version and 811 // asserting if this happens during startup, call the real sysctlnametomib() 812 // followed by internal_sysctl() if the syscall is not available. 813 #ifdef SYS___sysctlbyname 814 return internal_syscall(SYSCALL(__sysctlbyname), sname, 815 internal_strlen(sname), oldp, (size_t *)oldlenp, newp, 816 (size_t)newlen); 817 #else 818 static decltype(sysctlnametomib) *real_sysctlnametomib = nullptr; 819 if (!real_sysctlnametomib) 820 real_sysctlnametomib = 821 (decltype(sysctlnametomib) *)dlsym(RTLD_NEXT, "sysctlnametomib"); 822 CHECK(real_sysctlnametomib); 823 824 int oid[CTL_MAXNAME]; 825 size_t len = CTL_MAXNAME; 826 if (real_sysctlnametomib(sname, oid, &len) == -1) 827 return (-1); 828 return internal_sysctl(oid, len, oldp, oldlenp, newp, newlen); 829 #endif 830 } 831 #endif 832 #endif 833 834 #if SANITIZER_LINUX 835 #define SA_RESTORER 0x04000000 836 // Doesn't set sa_restorer if the caller did not set it, so use with caution 837 //(see below). 838 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) { 839 __sanitizer_kernel_sigaction_t k_act, k_oldact; 840 internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t)); 841 internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t)); 842 const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act; 843 __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact; 844 if (u_act) { 845 k_act.handler = u_act->handler; 846 k_act.sigaction = u_act->sigaction; 847 internal_memcpy(&k_act.sa_mask, &u_act->sa_mask, 848 sizeof(__sanitizer_kernel_sigset_t)); 849 // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL). 850 k_act.sa_flags = u_act->sa_flags | SA_RESTORER; 851 // FIXME: most often sa_restorer is unset, however the kernel requires it 852 // to point to a valid signal restorer that calls the rt_sigreturn syscall. 853 // If sa_restorer passed to the kernel is NULL, the program may crash upon 854 // signal delivery or fail to unwind the stack in the signal handler. 855 // libc implementation of sigaction() passes its own restorer to 856 // rt_sigaction, so we need to do the same (we'll need to reimplement the 857 // restorers; for x86_64 the restorer address can be obtained from 858 // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact). 859 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32 860 k_act.sa_restorer = u_act->sa_restorer; 861 #endif 862 } 863 864 uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum, 865 (uptr)(u_act ? &k_act : nullptr), 866 (uptr)(u_oldact ? &k_oldact : nullptr), 867 (uptr)sizeof(__sanitizer_kernel_sigset_t)); 868 869 if ((result == 0) && u_oldact) { 870 u_oldact->handler = k_oldact.handler; 871 u_oldact->sigaction = k_oldact.sigaction; 872 internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask, 873 sizeof(__sanitizer_kernel_sigset_t)); 874 u_oldact->sa_flags = k_oldact.sa_flags; 875 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32 876 u_oldact->sa_restorer = k_oldact.sa_restorer; 877 #endif 878 } 879 return result; 880 } 881 #endif // SANITIZER_LINUX 882 883 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set, 884 __sanitizer_sigset_t *oldset) { 885 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD 886 return internal_syscall(SYSCALL(sigprocmask), how, set, oldset); 887 #else 888 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 889 __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset; 890 return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how, (uptr)k_set, 891 (uptr)k_oldset, sizeof(__sanitizer_kernel_sigset_t)); 892 #endif 893 } 894 895 void internal_sigfillset(__sanitizer_sigset_t *set) { 896 internal_memset(set, 0xff, sizeof(*set)); 897 } 898 899 void internal_sigemptyset(__sanitizer_sigset_t *set) { 900 internal_memset(set, 0, sizeof(*set)); 901 } 902 903 #if SANITIZER_LINUX 904 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) { 905 signum -= 1; 906 CHECK_GE(signum, 0); 907 CHECK_LT(signum, sizeof(*set) * 8); 908 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 909 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8); 910 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8); 911 k_set->sig[idx] &= ~(1 << bit); 912 } 913 914 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) { 915 signum -= 1; 916 CHECK_GE(signum, 0); 917 CHECK_LT(signum, sizeof(*set) * 8); 918 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 919 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8); 920 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8); 921 return k_set->sig[idx] & (1 << bit); 922 } 923 #elif SANITIZER_FREEBSD 924 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) { 925 sigset_t *rset = reinterpret_cast<sigset_t *>(set); 926 sigdelset(rset, signum); 927 } 928 929 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) { 930 sigset_t *rset = reinterpret_cast<sigset_t *>(set); 931 return sigismember(rset, signum); 932 } 933 #endif 934 #endif // !SANITIZER_SOLARIS 935 936 #if !SANITIZER_NETBSD 937 // ThreadLister implementation. 938 ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) { 939 char task_directory_path[80]; 940 internal_snprintf(task_directory_path, sizeof(task_directory_path), 941 "/proc/%d/task/", pid); 942 descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY); 943 if (internal_iserror(descriptor_)) { 944 Report("Can't open /proc/%d/task for reading.\n", pid); 945 } 946 } 947 948 ThreadLister::Result ThreadLister::ListThreads( 949 InternalMmapVector<tid_t> *threads) { 950 if (internal_iserror(descriptor_)) 951 return Error; 952 internal_lseek(descriptor_, 0, SEEK_SET); 953 threads->clear(); 954 955 Result result = Ok; 956 for (bool first_read = true;; first_read = false) { 957 // Resize to max capacity if it was downsized by IsAlive. 958 buffer_.resize(buffer_.capacity()); 959 CHECK_GE(buffer_.size(), 4096); 960 uptr read = internal_getdents( 961 descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size()); 962 if (!read) 963 return result; 964 if (internal_iserror(read)) { 965 Report("Can't read directory entries from /proc/%d/task.\n", pid_); 966 return Error; 967 } 968 969 for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) { 970 struct linux_dirent *entry = (struct linux_dirent *)begin; 971 begin += entry->d_reclen; 972 if (entry->d_ino == 1) { 973 // Inode 1 is for bad blocks and also can be a reason for early return. 974 // Should be emitted if kernel tried to output terminating thread. 975 // See proc_task_readdir implementation in Linux. 976 result = Incomplete; 977 } 978 if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9') 979 threads->push_back(internal_atoll(entry->d_name)); 980 } 981 982 // Now we are going to detect short-read or early EOF. In such cases Linux 983 // can return inconsistent list with missing alive threads. 984 // Code will just remember that the list can be incomplete but it will 985 // continue reads to return as much as possible. 986 if (!first_read) { 987 // The first one was a short-read by definition. 988 result = Incomplete; 989 } else if (read > buffer_.size() - 1024) { 990 // Read was close to the buffer size. So double the size and assume the 991 // worst. 992 buffer_.resize(buffer_.size() * 2); 993 result = Incomplete; 994 } else if (!threads->empty() && !IsAlive(threads->back())) { 995 // Maybe Linux early returned from read on terminated thread (!pid_alive) 996 // and failed to restore read position. 997 // See next_tid and proc_task_instantiate in Linux. 998 result = Incomplete; 999 } 1000 } 1001 } 1002 1003 bool ThreadLister::IsAlive(int tid) { 1004 // /proc/%d/task/%d/status uses same call to detect alive threads as 1005 // proc_task_readdir. See task_state implementation in Linux. 1006 char path[80]; 1007 internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid); 1008 if (!ReadFileToVector(path, &buffer_) || buffer_.empty()) 1009 return false; 1010 buffer_.push_back(0); 1011 static const char kPrefix[] = "\nPPid:"; 1012 const char *field = internal_strstr(buffer_.data(), kPrefix); 1013 if (!field) 1014 return false; 1015 field += internal_strlen(kPrefix); 1016 return (int)internal_atoll(field) != 0; 1017 } 1018 1019 ThreadLister::~ThreadLister() { 1020 if (!internal_iserror(descriptor_)) 1021 internal_close(descriptor_); 1022 } 1023 #endif 1024 1025 #if SANITIZER_WORDSIZE == 32 1026 // Take care of unusable kernel area in top gigabyte. 1027 static uptr GetKernelAreaSize() { 1028 #if SANITIZER_LINUX && !SANITIZER_X32 1029 const uptr gbyte = 1UL << 30; 1030 1031 // Firstly check if there are writable segments 1032 // mapped to top gigabyte (e.g. stack). 1033 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 1034 if (proc_maps.Error()) 1035 return 0; 1036 MemoryMappedSegment segment; 1037 while (proc_maps.Next(&segment)) { 1038 if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0; 1039 } 1040 1041 #if !SANITIZER_ANDROID 1042 // Even if nothing is mapped, top Gb may still be accessible 1043 // if we are running on 64-bit kernel. 1044 // Uname may report misleading results if personality type 1045 // is modified (e.g. under schroot) so check this as well. 1046 struct utsname uname_info; 1047 int pers = personality(0xffffffffUL); 1048 if (!(pers & PER_MASK) && internal_uname(&uname_info) == 0 && 1049 internal_strstr(uname_info.machine, "64")) 1050 return 0; 1051 #endif // SANITIZER_ANDROID 1052 1053 // Top gigabyte is reserved for kernel. 1054 return gbyte; 1055 #else 1056 return 0; 1057 #endif // SANITIZER_LINUX && !SANITIZER_X32 1058 } 1059 #endif // SANITIZER_WORDSIZE == 32 1060 1061 uptr GetMaxVirtualAddress() { 1062 #if (SANITIZER_NETBSD || SANITIZER_OPENBSD) && defined(__x86_64__) 1063 return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE) 1064 #elif SANITIZER_WORDSIZE == 64 1065 # if defined(__powerpc64__) || defined(__aarch64__) 1066 // On PowerPC64 we have two different address space layouts: 44- and 46-bit. 1067 // We somehow need to figure out which one we are using now and choose 1068 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL. 1069 // Note that with 'ulimit -s unlimited' the stack is moved away from the top 1070 // of the address space, so simply checking the stack address is not enough. 1071 // This should (does) work for both PowerPC64 Endian modes. 1072 // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit. 1073 return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1; 1074 #elif SANITIZER_RISCV64 1075 return (1ULL << 38) - 1; 1076 # elif defined(__mips64) 1077 return (1ULL << 40) - 1; // 0x000000ffffffffffUL; 1078 # elif defined(__s390x__) 1079 return (1ULL << 53) - 1; // 0x001fffffffffffffUL; 1080 #elif defined(__sparc__) 1081 return ~(uptr)0; 1082 # else 1083 return (1ULL << 47) - 1; // 0x00007fffffffffffUL; 1084 # endif 1085 #else // SANITIZER_WORDSIZE == 32 1086 # if defined(__s390__) 1087 return (1ULL << 31) - 1; // 0x7fffffff; 1088 # else 1089 return (1ULL << 32) - 1; // 0xffffffff; 1090 # endif 1091 #endif // SANITIZER_WORDSIZE 1092 } 1093 1094 uptr GetMaxUserVirtualAddress() { 1095 uptr addr = GetMaxVirtualAddress(); 1096 #if SANITIZER_WORDSIZE == 32 && !defined(__s390__) 1097 if (!common_flags()->full_address_space) 1098 addr -= GetKernelAreaSize(); 1099 CHECK_LT(reinterpret_cast<uptr>(&addr), addr); 1100 #endif 1101 return addr; 1102 } 1103 1104 #if !SANITIZER_ANDROID 1105 uptr GetPageSize() { 1106 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) && \ 1107 defined(EXEC_PAGESIZE) 1108 return EXEC_PAGESIZE; 1109 #elif SANITIZER_FREEBSD || SANITIZER_NETBSD 1110 // Use sysctl as sysconf can trigger interceptors internally. 1111 int pz = 0; 1112 uptr pzl = sizeof(pz); 1113 int mib[2] = {CTL_HW, HW_PAGESIZE}; 1114 int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0); 1115 CHECK_EQ(rv, 0); 1116 return (uptr)pz; 1117 #elif SANITIZER_USE_GETAUXVAL 1118 return getauxval(AT_PAGESZ); 1119 #else 1120 return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy. 1121 #endif 1122 } 1123 #endif // !SANITIZER_ANDROID 1124 1125 #if !SANITIZER_OPENBSD 1126 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) { 1127 #if SANITIZER_SOLARIS 1128 const char *default_module_name = getexecname(); 1129 CHECK_NE(default_module_name, NULL); 1130 return internal_snprintf(buf, buf_len, "%s", default_module_name); 1131 #else 1132 #if SANITIZER_FREEBSD || SANITIZER_NETBSD 1133 #if SANITIZER_FREEBSD 1134 const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1}; 1135 #else 1136 const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME}; 1137 #endif 1138 const char *default_module_name = "kern.proc.pathname"; 1139 uptr Size = buf_len; 1140 bool IsErr = 1141 (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0); 1142 int readlink_error = IsErr ? errno : 0; 1143 uptr module_name_len = Size; 1144 #else 1145 const char *default_module_name = "/proc/self/exe"; 1146 uptr module_name_len = internal_readlink( 1147 default_module_name, buf, buf_len); 1148 int readlink_error; 1149 bool IsErr = internal_iserror(module_name_len, &readlink_error); 1150 #endif // SANITIZER_SOLARIS 1151 if (IsErr) { 1152 // We can't read binary name for some reason, assume it's unknown. 1153 Report("WARNING: reading executable name failed with errno %d, " 1154 "some stack frames may not be symbolized\n", readlink_error); 1155 module_name_len = internal_snprintf(buf, buf_len, "%s", 1156 default_module_name); 1157 CHECK_LT(module_name_len, buf_len); 1158 } 1159 return module_name_len; 1160 #endif 1161 } 1162 #endif // !SANITIZER_OPENBSD 1163 1164 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) { 1165 #if SANITIZER_LINUX 1166 char *tmpbuf; 1167 uptr tmpsize; 1168 uptr tmplen; 1169 if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen, 1170 1024 * 1024)) { 1171 internal_strncpy(buf, tmpbuf, buf_len); 1172 UnmapOrDie(tmpbuf, tmpsize); 1173 return internal_strlen(buf); 1174 } 1175 #endif 1176 return ReadBinaryName(buf, buf_len); 1177 } 1178 1179 // Match full names of the form /path/to/base_name{-,.}* 1180 bool LibraryNameIs(const char *full_name, const char *base_name) { 1181 const char *name = full_name; 1182 // Strip path. 1183 while (*name != '\0') name++; 1184 while (name > full_name && *name != '/') name--; 1185 if (*name == '/') name++; 1186 uptr base_name_length = internal_strlen(base_name); 1187 if (internal_strncmp(name, base_name, base_name_length)) return false; 1188 return (name[base_name_length] == '-' || name[base_name_length] == '.'); 1189 } 1190 1191 #if !SANITIZER_ANDROID 1192 // Call cb for each region mapped by map. 1193 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) { 1194 CHECK_NE(map, nullptr); 1195 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 1196 typedef ElfW(Phdr) Elf_Phdr; 1197 typedef ElfW(Ehdr) Elf_Ehdr; 1198 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 1199 char *base = (char *)map->l_addr; 1200 Elf_Ehdr *ehdr = (Elf_Ehdr *)base; 1201 char *phdrs = base + ehdr->e_phoff; 1202 char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize; 1203 1204 // Find the segment with the minimum base so we can "relocate" the p_vaddr 1205 // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC 1206 // objects have a non-zero base. 1207 uptr preferred_base = (uptr)-1; 1208 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { 1209 Elf_Phdr *phdr = (Elf_Phdr *)iter; 1210 if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr) 1211 preferred_base = (uptr)phdr->p_vaddr; 1212 } 1213 1214 // Compute the delta from the real base to get a relocation delta. 1215 sptr delta = (uptr)base - preferred_base; 1216 // Now we can figure out what the loader really mapped. 1217 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { 1218 Elf_Phdr *phdr = (Elf_Phdr *)iter; 1219 if (phdr->p_type == PT_LOAD) { 1220 uptr seg_start = phdr->p_vaddr + delta; 1221 uptr seg_end = seg_start + phdr->p_memsz; 1222 // None of these values are aligned. We consider the ragged edges of the 1223 // load command as defined, since they are mapped from the file. 1224 seg_start = RoundDownTo(seg_start, GetPageSizeCached()); 1225 seg_end = RoundUpTo(seg_end, GetPageSizeCached()); 1226 cb((void *)seg_start, seg_end - seg_start); 1227 } 1228 } 1229 } 1230 #endif 1231 1232 #if defined(__x86_64__) && SANITIZER_LINUX 1233 // We cannot use glibc's clone wrapper, because it messes with the child 1234 // task's TLS. It writes the PID and TID of the child task to its thread 1235 // descriptor, but in our case the child task shares the thread descriptor with 1236 // the parent (because we don't know how to allocate a new thread 1237 // descriptor to keep glibc happy). So the stock version of clone(), when 1238 // used with CLONE_VM, would end up corrupting the parent's thread descriptor. 1239 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1240 int *parent_tidptr, void *newtls, int *child_tidptr) { 1241 long long res; 1242 if (!fn || !child_stack) 1243 return -EINVAL; 1244 CHECK_EQ(0, (uptr)child_stack % 16); 1245 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1246 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1247 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1248 register void *r8 __asm__("r8") = newtls; 1249 register int *r10 __asm__("r10") = child_tidptr; 1250 __asm__ __volatile__( 1251 /* %rax = syscall(%rax = SYSCALL(clone), 1252 * %rdi = flags, 1253 * %rsi = child_stack, 1254 * %rdx = parent_tidptr, 1255 * %r8 = new_tls, 1256 * %r10 = child_tidptr) 1257 */ 1258 "syscall\n" 1259 1260 /* if (%rax != 0) 1261 * return; 1262 */ 1263 "testq %%rax,%%rax\n" 1264 "jnz 1f\n" 1265 1266 /* In the child. Terminate unwind chain. */ 1267 // XXX: We should also terminate the CFI unwind chain 1268 // here. Unfortunately clang 3.2 doesn't support the 1269 // necessary CFI directives, so we skip that part. 1270 "xorq %%rbp,%%rbp\n" 1271 1272 /* Call "fn(arg)". */ 1273 "popq %%rax\n" 1274 "popq %%rdi\n" 1275 "call *%%rax\n" 1276 1277 /* Call _exit(%rax). */ 1278 "movq %%rax,%%rdi\n" 1279 "movq %2,%%rax\n" 1280 "syscall\n" 1281 1282 /* Return to parent. */ 1283 "1:\n" 1284 : "=a" (res) 1285 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), 1286 "S"(child_stack), 1287 "D"(flags), 1288 "d"(parent_tidptr), 1289 "r"(r8), 1290 "r"(r10) 1291 : "memory", "r11", "rcx"); 1292 return res; 1293 } 1294 #elif defined(__mips__) 1295 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1296 int *parent_tidptr, void *newtls, int *child_tidptr) { 1297 long long res; 1298 if (!fn || !child_stack) 1299 return -EINVAL; 1300 CHECK_EQ(0, (uptr)child_stack % 16); 1301 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1302 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1303 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1304 register void *a3 __asm__("$7") = newtls; 1305 register int *a4 __asm__("$8") = child_tidptr; 1306 // We don't have proper CFI directives here because it requires alot of code 1307 // for very marginal benefits. 1308 __asm__ __volatile__( 1309 /* $v0 = syscall($v0 = __NR_clone, 1310 * $a0 = flags, 1311 * $a1 = child_stack, 1312 * $a2 = parent_tidptr, 1313 * $a3 = new_tls, 1314 * $a4 = child_tidptr) 1315 */ 1316 ".cprestore 16;\n" 1317 "move $4,%1;\n" 1318 "move $5,%2;\n" 1319 "move $6,%3;\n" 1320 "move $7,%4;\n" 1321 /* Store the fifth argument on stack 1322 * if we are using 32-bit abi. 1323 */ 1324 #if SANITIZER_WORDSIZE == 32 1325 "lw %5,16($29);\n" 1326 #else 1327 "move $8,%5;\n" 1328 #endif 1329 "li $2,%6;\n" 1330 "syscall;\n" 1331 1332 /* if ($v0 != 0) 1333 * return; 1334 */ 1335 "bnez $2,1f;\n" 1336 1337 /* Call "fn(arg)". */ 1338 #if SANITIZER_WORDSIZE == 32 1339 #ifdef __BIG_ENDIAN__ 1340 "lw $25,4($29);\n" 1341 "lw $4,12($29);\n" 1342 #else 1343 "lw $25,0($29);\n" 1344 "lw $4,8($29);\n" 1345 #endif 1346 #else 1347 "ld $25,0($29);\n" 1348 "ld $4,8($29);\n" 1349 #endif 1350 "jal $25;\n" 1351 1352 /* Call _exit($v0). */ 1353 "move $4,$2;\n" 1354 "li $2,%7;\n" 1355 "syscall;\n" 1356 1357 /* Return to parent. */ 1358 "1:\n" 1359 : "=r" (res) 1360 : "r"(flags), 1361 "r"(child_stack), 1362 "r"(parent_tidptr), 1363 "r"(a3), 1364 "r"(a4), 1365 "i"(__NR_clone), 1366 "i"(__NR_exit) 1367 : "memory", "$29" ); 1368 return res; 1369 } 1370 #elif SANITIZER_RISCV64 1371 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1372 int *parent_tidptr, void *newtls, int *child_tidptr) { 1373 long long res; 1374 if (!fn || !child_stack) 1375 return -EINVAL; 1376 CHECK_EQ(0, (uptr)child_stack % 16); 1377 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1378 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1379 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1380 1381 register int (*__fn)(void *) __asm__("a0") = fn; 1382 register void *__stack __asm__("a1") = child_stack; 1383 register int __flags __asm__("a2") = flags; 1384 register void *__arg __asm__("a3") = arg; 1385 register int *__ptid __asm__("a4") = parent_tidptr; 1386 register void *__tls __asm__("a5") = newtls; 1387 register int *__ctid __asm__("a6") = child_tidptr; 1388 1389 __asm__ __volatile__( 1390 "mv a0,a2\n" /* flags */ 1391 "mv a2,a4\n" /* ptid */ 1392 "mv a3,a5\n" /* tls */ 1393 "mv a4,a6\n" /* ctid */ 1394 "addi a7, zero, %9\n" /* clone */ 1395 1396 "ecall\n" 1397 1398 /* if (%r0 != 0) 1399 * return %r0; 1400 */ 1401 "bnez a0, 1f\n" 1402 1403 /* In the child, now. Call "fn(arg)". */ 1404 "ld a0, 8(sp)\n" 1405 "ld a1, 16(sp)\n" 1406 "jalr a1\n" 1407 1408 /* Call _exit(%r0). */ 1409 "addi a7, zero, %10\n" 1410 "ecall\n" 1411 "1:\n" 1412 1413 : "=r"(res) 1414 : "i"(-EINVAL), "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg), 1415 "r"(__ptid), "r"(__tls), "r"(__ctid), "i"(__NR_clone), "i"(__NR_exit) 1416 : "ra", "memory"); 1417 return res; 1418 } 1419 #elif defined(__aarch64__) 1420 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1421 int *parent_tidptr, void *newtls, int *child_tidptr) { 1422 long long res; 1423 if (!fn || !child_stack) 1424 return -EINVAL; 1425 CHECK_EQ(0, (uptr)child_stack % 16); 1426 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1427 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1428 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1429 1430 register int (*__fn)(void *) __asm__("x0") = fn; 1431 register void *__stack __asm__("x1") = child_stack; 1432 register int __flags __asm__("x2") = flags; 1433 register void *__arg __asm__("x3") = arg; 1434 register int *__ptid __asm__("x4") = parent_tidptr; 1435 register void *__tls __asm__("x5") = newtls; 1436 register int *__ctid __asm__("x6") = child_tidptr; 1437 1438 __asm__ __volatile__( 1439 "mov x0,x2\n" /* flags */ 1440 "mov x2,x4\n" /* ptid */ 1441 "mov x3,x5\n" /* tls */ 1442 "mov x4,x6\n" /* ctid */ 1443 "mov x8,%9\n" /* clone */ 1444 1445 "svc 0x0\n" 1446 1447 /* if (%r0 != 0) 1448 * return %r0; 1449 */ 1450 "cmp x0, #0\n" 1451 "bne 1f\n" 1452 1453 /* In the child, now. Call "fn(arg)". */ 1454 "ldp x1, x0, [sp], #16\n" 1455 "blr x1\n" 1456 1457 /* Call _exit(%r0). */ 1458 "mov x8, %10\n" 1459 "svc 0x0\n" 1460 "1:\n" 1461 1462 : "=r" (res) 1463 : "i"(-EINVAL), 1464 "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg), 1465 "r"(__ptid), "r"(__tls), "r"(__ctid), 1466 "i"(__NR_clone), "i"(__NR_exit) 1467 : "x30", "memory"); 1468 return res; 1469 } 1470 #elif defined(__powerpc64__) 1471 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1472 int *parent_tidptr, void *newtls, int *child_tidptr) { 1473 long long res; 1474 // Stack frame structure. 1475 #if SANITIZER_PPC64V1 1476 // Back chain == 0 (SP + 112) 1477 // Frame (112 bytes): 1478 // Parameter save area (SP + 48), 8 doublewords 1479 // TOC save area (SP + 40) 1480 // Link editor doubleword (SP + 32) 1481 // Compiler doubleword (SP + 24) 1482 // LR save area (SP + 16) 1483 // CR save area (SP + 8) 1484 // Back chain (SP + 0) 1485 # define FRAME_SIZE 112 1486 # define FRAME_TOC_SAVE_OFFSET 40 1487 #elif SANITIZER_PPC64V2 1488 // Back chain == 0 (SP + 32) 1489 // Frame (32 bytes): 1490 // TOC save area (SP + 24) 1491 // LR save area (SP + 16) 1492 // CR save area (SP + 8) 1493 // Back chain (SP + 0) 1494 # define FRAME_SIZE 32 1495 # define FRAME_TOC_SAVE_OFFSET 24 1496 #else 1497 # error "Unsupported PPC64 ABI" 1498 #endif 1499 if (!fn || !child_stack) 1500 return -EINVAL; 1501 CHECK_EQ(0, (uptr)child_stack % 16); 1502 1503 register int (*__fn)(void *) __asm__("r3") = fn; 1504 register void *__cstack __asm__("r4") = child_stack; 1505 register int __flags __asm__("r5") = flags; 1506 register void *__arg __asm__("r6") = arg; 1507 register int *__ptidptr __asm__("r7") = parent_tidptr; 1508 register void *__newtls __asm__("r8") = newtls; 1509 register int *__ctidptr __asm__("r9") = child_tidptr; 1510 1511 __asm__ __volatile__( 1512 /* fn and arg are saved across the syscall */ 1513 "mr 28, %5\n\t" 1514 "mr 27, %8\n\t" 1515 1516 /* syscall 1517 r0 == __NR_clone 1518 r3 == flags 1519 r4 == child_stack 1520 r5 == parent_tidptr 1521 r6 == newtls 1522 r7 == child_tidptr */ 1523 "mr 3, %7\n\t" 1524 "mr 5, %9\n\t" 1525 "mr 6, %10\n\t" 1526 "mr 7, %11\n\t" 1527 "li 0, %3\n\t" 1528 "sc\n\t" 1529 1530 /* Test if syscall was successful */ 1531 "cmpdi cr1, 3, 0\n\t" 1532 "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t" 1533 "bne- cr1, 1f\n\t" 1534 1535 /* Set up stack frame */ 1536 "li 29, 0\n\t" 1537 "stdu 29, -8(1)\n\t" 1538 "stdu 1, -%12(1)\n\t" 1539 /* Do the function call */ 1540 "std 2, %13(1)\n\t" 1541 #if SANITIZER_PPC64V1 1542 "ld 0, 0(28)\n\t" 1543 "ld 2, 8(28)\n\t" 1544 "mtctr 0\n\t" 1545 #elif SANITIZER_PPC64V2 1546 "mr 12, 28\n\t" 1547 "mtctr 12\n\t" 1548 #else 1549 # error "Unsupported PPC64 ABI" 1550 #endif 1551 "mr 3, 27\n\t" 1552 "bctrl\n\t" 1553 "ld 2, %13(1)\n\t" 1554 1555 /* Call _exit(r3) */ 1556 "li 0, %4\n\t" 1557 "sc\n\t" 1558 1559 /* Return to parent */ 1560 "1:\n\t" 1561 "mr %0, 3\n\t" 1562 : "=r" (res) 1563 : "0" (-1), 1564 "i" (EINVAL), 1565 "i" (__NR_clone), 1566 "i" (__NR_exit), 1567 "r" (__fn), 1568 "r" (__cstack), 1569 "r" (__flags), 1570 "r" (__arg), 1571 "r" (__ptidptr), 1572 "r" (__newtls), 1573 "r" (__ctidptr), 1574 "i" (FRAME_SIZE), 1575 "i" (FRAME_TOC_SAVE_OFFSET) 1576 : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29"); 1577 return res; 1578 } 1579 #elif defined(__i386__) && SANITIZER_LINUX 1580 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1581 int *parent_tidptr, void *newtls, int *child_tidptr) { 1582 int res; 1583 if (!fn || !child_stack) 1584 return -EINVAL; 1585 CHECK_EQ(0, (uptr)child_stack % 16); 1586 child_stack = (char *)child_stack - 7 * sizeof(unsigned int); 1587 ((unsigned int *)child_stack)[0] = (uptr)flags; 1588 ((unsigned int *)child_stack)[1] = (uptr)0; 1589 ((unsigned int *)child_stack)[2] = (uptr)fn; 1590 ((unsigned int *)child_stack)[3] = (uptr)arg; 1591 __asm__ __volatile__( 1592 /* %eax = syscall(%eax = SYSCALL(clone), 1593 * %ebx = flags, 1594 * %ecx = child_stack, 1595 * %edx = parent_tidptr, 1596 * %esi = new_tls, 1597 * %edi = child_tidptr) 1598 */ 1599 1600 /* Obtain flags */ 1601 "movl (%%ecx), %%ebx\n" 1602 /* Do the system call */ 1603 "pushl %%ebx\n" 1604 "pushl %%esi\n" 1605 "pushl %%edi\n" 1606 /* Remember the flag value. */ 1607 "movl %%ebx, (%%ecx)\n" 1608 "int $0x80\n" 1609 "popl %%edi\n" 1610 "popl %%esi\n" 1611 "popl %%ebx\n" 1612 1613 /* if (%eax != 0) 1614 * return; 1615 */ 1616 1617 "test %%eax,%%eax\n" 1618 "jnz 1f\n" 1619 1620 /* terminate the stack frame */ 1621 "xorl %%ebp,%%ebp\n" 1622 /* Call FN. */ 1623 "call *%%ebx\n" 1624 #ifdef PIC 1625 "call here\n" 1626 "here:\n" 1627 "popl %%ebx\n" 1628 "addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n" 1629 #endif 1630 /* Call exit */ 1631 "movl %%eax, %%ebx\n" 1632 "movl %2, %%eax\n" 1633 "int $0x80\n" 1634 "1:\n" 1635 : "=a" (res) 1636 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), 1637 "c"(child_stack), 1638 "d"(parent_tidptr), 1639 "S"(newtls), 1640 "D"(child_tidptr) 1641 : "memory"); 1642 return res; 1643 } 1644 #elif defined(__arm__) && SANITIZER_LINUX 1645 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1646 int *parent_tidptr, void *newtls, int *child_tidptr) { 1647 unsigned int res; 1648 if (!fn || !child_stack) 1649 return -EINVAL; 1650 child_stack = (char *)child_stack - 2 * sizeof(unsigned int); 1651 ((unsigned int *)child_stack)[0] = (uptr)fn; 1652 ((unsigned int *)child_stack)[1] = (uptr)arg; 1653 register int r0 __asm__("r0") = flags; 1654 register void *r1 __asm__("r1") = child_stack; 1655 register int *r2 __asm__("r2") = parent_tidptr; 1656 register void *r3 __asm__("r3") = newtls; 1657 register int *r4 __asm__("r4") = child_tidptr; 1658 register int r7 __asm__("r7") = __NR_clone; 1659 1660 #if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__) 1661 # define ARCH_HAS_BX 1662 #endif 1663 #if __ARM_ARCH > 4 1664 # define ARCH_HAS_BLX 1665 #endif 1666 1667 #ifdef ARCH_HAS_BX 1668 # ifdef ARCH_HAS_BLX 1669 # define BLX(R) "blx " #R "\n" 1670 # else 1671 # define BLX(R) "mov lr, pc; bx " #R "\n" 1672 # endif 1673 #else 1674 # define BLX(R) "mov lr, pc; mov pc," #R "\n" 1675 #endif 1676 1677 __asm__ __volatile__( 1678 /* %r0 = syscall(%r7 = SYSCALL(clone), 1679 * %r0 = flags, 1680 * %r1 = child_stack, 1681 * %r2 = parent_tidptr, 1682 * %r3 = new_tls, 1683 * %r4 = child_tidptr) 1684 */ 1685 1686 /* Do the system call */ 1687 "swi 0x0\n" 1688 1689 /* if (%r0 != 0) 1690 * return %r0; 1691 */ 1692 "cmp r0, #0\n" 1693 "bne 1f\n" 1694 1695 /* In the child, now. Call "fn(arg)". */ 1696 "ldr r0, [sp, #4]\n" 1697 "ldr ip, [sp], #8\n" 1698 BLX(ip) 1699 /* Call _exit(%r0). */ 1700 "mov r7, %7\n" 1701 "swi 0x0\n" 1702 "1:\n" 1703 "mov %0, r0\n" 1704 : "=r"(res) 1705 : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7), 1706 "i"(__NR_exit) 1707 : "memory"); 1708 return res; 1709 } 1710 #endif // defined(__x86_64__) && SANITIZER_LINUX 1711 1712 #if SANITIZER_LINUX 1713 int internal_uname(struct utsname *buf) { 1714 return internal_syscall(SYSCALL(uname), buf); 1715 } 1716 #endif 1717 1718 #if SANITIZER_ANDROID 1719 #if __ANDROID_API__ < 21 1720 extern "C" __attribute__((weak)) int dl_iterate_phdr( 1721 int (*)(struct dl_phdr_info *, size_t, void *), void *); 1722 #endif 1723 1724 static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size, 1725 void *data) { 1726 // Any name starting with "lib" indicates a bug in L where library base names 1727 // are returned instead of paths. 1728 if (info->dlpi_name && info->dlpi_name[0] == 'l' && 1729 info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') { 1730 *(bool *)data = true; 1731 return 1; 1732 } 1733 return 0; 1734 } 1735 1736 static atomic_uint32_t android_api_level; 1737 1738 static AndroidApiLevel AndroidDetectApiLevelStatic() { 1739 #if __ANDROID_API__ <= 19 1740 return ANDROID_KITKAT; 1741 #elif __ANDROID_API__ <= 22 1742 return ANDROID_LOLLIPOP_MR1; 1743 #else 1744 return ANDROID_POST_LOLLIPOP; 1745 #endif 1746 } 1747 1748 static AndroidApiLevel AndroidDetectApiLevel() { 1749 if (!&dl_iterate_phdr) 1750 return ANDROID_KITKAT; // K or lower 1751 bool base_name_seen = false; 1752 dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen); 1753 if (base_name_seen) 1754 return ANDROID_LOLLIPOP_MR1; // L MR1 1755 return ANDROID_POST_LOLLIPOP; // post-L 1756 // Plain L (API level 21) is completely broken wrt ASan and not very 1757 // interesting to detect. 1758 } 1759 1760 extern "C" __attribute__((weak)) void* _DYNAMIC; 1761 1762 AndroidApiLevel AndroidGetApiLevel() { 1763 AndroidApiLevel level = 1764 (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed); 1765 if (level) return level; 1766 level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic() 1767 : AndroidDetectApiLevel(); 1768 atomic_store(&android_api_level, level, memory_order_relaxed); 1769 return level; 1770 } 1771 1772 #endif 1773 1774 static HandleSignalMode GetHandleSignalModeImpl(int signum) { 1775 switch (signum) { 1776 case SIGABRT: 1777 return common_flags()->handle_abort; 1778 case SIGILL: 1779 return common_flags()->handle_sigill; 1780 case SIGTRAP: 1781 return common_flags()->handle_sigtrap; 1782 case SIGFPE: 1783 return common_flags()->handle_sigfpe; 1784 case SIGSEGV: 1785 return common_flags()->handle_segv; 1786 case SIGBUS: 1787 return common_flags()->handle_sigbus; 1788 } 1789 return kHandleSignalNo; 1790 } 1791 1792 HandleSignalMode GetHandleSignalMode(int signum) { 1793 HandleSignalMode result = GetHandleSignalModeImpl(signum); 1794 if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler) 1795 return kHandleSignalExclusive; 1796 return result; 1797 } 1798 1799 #if !SANITIZER_GO 1800 void *internal_start_thread(void *(*func)(void *arg), void *arg) { 1801 // Start the thread with signals blocked, otherwise it can steal user signals. 1802 __sanitizer_sigset_t set, old; 1803 internal_sigfillset(&set); 1804 #if SANITIZER_LINUX && !SANITIZER_ANDROID 1805 // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked 1806 // on any thread, setuid call hangs (see test/tsan/setuid.c). 1807 internal_sigdelset(&set, 33); 1808 #endif 1809 internal_sigprocmask(SIG_SETMASK, &set, &old); 1810 void *th; 1811 real_pthread_create(&th, nullptr, func, arg); 1812 internal_sigprocmask(SIG_SETMASK, &old, nullptr); 1813 return th; 1814 } 1815 1816 void internal_join_thread(void *th) { 1817 real_pthread_join(th, nullptr); 1818 } 1819 #else 1820 void *internal_start_thread(void *(*func)(void *), void *arg) { return 0; } 1821 1822 void internal_join_thread(void *th) {} 1823 #endif 1824 1825 #if defined(__aarch64__) 1826 // Android headers in the older NDK releases miss this definition. 1827 struct __sanitizer_esr_context { 1828 struct _aarch64_ctx head; 1829 uint64_t esr; 1830 }; 1831 1832 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) { 1833 static const u32 kEsrMagic = 0x45535201; 1834 u8 *aux = ucontext->uc_mcontext.__reserved; 1835 while (true) { 1836 _aarch64_ctx *ctx = (_aarch64_ctx *)aux; 1837 if (ctx->size == 0) break; 1838 if (ctx->magic == kEsrMagic) { 1839 *esr = ((__sanitizer_esr_context *)ctx)->esr; 1840 return true; 1841 } 1842 aux += ctx->size; 1843 } 1844 return false; 1845 } 1846 #endif 1847 1848 #if SANITIZER_OPENBSD 1849 using Context = sigcontext; 1850 #else 1851 using Context = ucontext_t; 1852 #endif 1853 1854 SignalContext::WriteFlag SignalContext::GetWriteFlag() const { 1855 Context *ucontext = (Context *)context; 1856 #if defined(__x86_64__) || defined(__i386__) 1857 static const uptr PF_WRITE = 1U << 1; 1858 #if SANITIZER_FREEBSD 1859 uptr err = ucontext->uc_mcontext.mc_err; 1860 #elif SANITIZER_NETBSD 1861 uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR]; 1862 #elif SANITIZER_OPENBSD 1863 uptr err = ucontext->sc_err; 1864 #elif SANITIZER_SOLARIS && defined(__i386__) 1865 const int Err = 13; 1866 uptr err = ucontext->uc_mcontext.gregs[Err]; 1867 #else 1868 uptr err = ucontext->uc_mcontext.gregs[REG_ERR]; 1869 #endif // SANITIZER_FREEBSD 1870 return err & PF_WRITE ? WRITE : READ; 1871 #elif defined(__mips__) 1872 uint32_t *exception_source; 1873 uint32_t faulty_instruction; 1874 uint32_t op_code; 1875 1876 exception_source = (uint32_t *)ucontext->uc_mcontext.pc; 1877 faulty_instruction = (uint32_t)(*exception_source); 1878 1879 op_code = (faulty_instruction >> 26) & 0x3f; 1880 1881 // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions. 1882 switch (op_code) { 1883 case 0x28: // sb 1884 case 0x29: // sh 1885 case 0x2b: // sw 1886 case 0x3f: // sd 1887 #if __mips_isa_rev < 6 1888 case 0x2c: // sdl 1889 case 0x2d: // sdr 1890 case 0x2a: // swl 1891 case 0x2e: // swr 1892 #endif 1893 return SignalContext::WRITE; 1894 1895 case 0x20: // lb 1896 case 0x24: // lbu 1897 case 0x21: // lh 1898 case 0x25: // lhu 1899 case 0x23: // lw 1900 case 0x27: // lwu 1901 case 0x37: // ld 1902 #if __mips_isa_rev < 6 1903 case 0x1a: // ldl 1904 case 0x1b: // ldr 1905 case 0x22: // lwl 1906 case 0x26: // lwr 1907 #endif 1908 return SignalContext::READ; 1909 #if __mips_isa_rev == 6 1910 case 0x3b: // pcrel 1911 op_code = (faulty_instruction >> 19) & 0x3; 1912 switch (op_code) { 1913 case 0x1: // lwpc 1914 case 0x2: // lwupc 1915 return SignalContext::READ; 1916 } 1917 #endif 1918 } 1919 return SignalContext::UNKNOWN; 1920 #elif defined(__arm__) 1921 static const uptr FSR_WRITE = 1U << 11; 1922 uptr fsr = ucontext->uc_mcontext.error_code; 1923 return fsr & FSR_WRITE ? WRITE : READ; 1924 #elif defined(__aarch64__) 1925 static const u64 ESR_ELx_WNR = 1U << 6; 1926 u64 esr; 1927 if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN; 1928 return esr & ESR_ELx_WNR ? WRITE : READ; 1929 #elif defined(__sparc__) 1930 // Decode the instruction to determine the access type. 1931 // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype). 1932 #if SANITIZER_SOLARIS 1933 uptr pc = ucontext->uc_mcontext.gregs[REG_PC]; 1934 #else 1935 // Historical BSDism here. 1936 struct sigcontext *scontext = (struct sigcontext *)context; 1937 #if defined(__arch64__) 1938 uptr pc = scontext->sigc_regs.tpc; 1939 #else 1940 uptr pc = scontext->si_regs.pc; 1941 #endif 1942 #endif 1943 u32 instr = *(u32 *)pc; 1944 return (instr >> 21) & 1 ? WRITE: READ; 1945 #elif defined(__riscv) 1946 unsigned long pc = ucontext->uc_mcontext.__gregs[REG_PC]; 1947 unsigned faulty_instruction = *(uint16_t *)pc; 1948 1949 #if defined(__riscv_compressed) 1950 if ((faulty_instruction & 0x3) != 0x3) { // it's a compressed instruction 1951 // set op_bits to the instruction bits [1, 0, 15, 14, 13] 1952 unsigned op_bits = 1953 ((faulty_instruction & 0x3) << 3) | (faulty_instruction >> 13); 1954 unsigned rd = faulty_instruction & 0xF80; // bits 7-11, inclusive 1955 switch (op_bits) { 1956 case 0b10'010: // c.lwsp (rd != x0) 1957 #if __riscv_xlen == 64 1958 case 0b10'011: // c.ldsp (rd != x0) 1959 #endif 1960 return rd ? SignalContext::READ : SignalContext::UNKNOWN; 1961 case 0b00'010: // c.lw 1962 #if __riscv_flen >= 32 && __riscv_xlen == 32 1963 case 0b10'011: // c.flwsp 1964 #endif 1965 #if __riscv_flen >= 32 || __riscv_xlen == 64 1966 case 0b00'011: // c.flw / c.ld 1967 #endif 1968 #if __riscv_flen == 64 1969 case 0b00'001: // c.fld 1970 case 0b10'001: // c.fldsp 1971 #endif 1972 return SignalContext::READ; 1973 case 0b00'110: // c.sw 1974 case 0b10'110: // c.swsp 1975 #if __riscv_flen >= 32 || __riscv_xlen == 64 1976 case 0b00'111: // c.fsw / c.sd 1977 case 0b10'111: // c.fswsp / c.sdsp 1978 #endif 1979 #if __riscv_flen == 64 1980 case 0b00'101: // c.fsd 1981 case 0b10'101: // c.fsdsp 1982 #endif 1983 return SignalContext::WRITE; 1984 default: 1985 return SignalContext::UNKNOWN; 1986 } 1987 } 1988 #endif 1989 1990 unsigned opcode = faulty_instruction & 0x7f; // lower 7 bits 1991 unsigned funct3 = (faulty_instruction >> 12) & 0x7; // bits 12-14, inclusive 1992 switch (opcode) { 1993 case 0b0000011: // loads 1994 switch (funct3) { 1995 case 0b000: // lb 1996 case 0b001: // lh 1997 case 0b010: // lw 1998 #if __riscv_xlen == 64 1999 case 0b011: // ld 2000 #endif 2001 case 0b100: // lbu 2002 case 0b101: // lhu 2003 return SignalContext::READ; 2004 default: 2005 return SignalContext::UNKNOWN; 2006 } 2007 case 0b0100011: // stores 2008 switch (funct3) { 2009 case 0b000: // sb 2010 case 0b001: // sh 2011 case 0b010: // sw 2012 #if __riscv_xlen == 64 2013 case 0b011: // sd 2014 #endif 2015 return SignalContext::WRITE; 2016 default: 2017 return SignalContext::UNKNOWN; 2018 } 2019 #if __riscv_flen >= 32 2020 case 0b0000111: // floating-point loads 2021 switch (funct3) { 2022 case 0b010: // flw 2023 #if __riscv_flen == 64 2024 case 0b011: // fld 2025 #endif 2026 return SignalContext::READ; 2027 default: 2028 return SignalContext::UNKNOWN; 2029 } 2030 case 0b0100111: // floating-point stores 2031 switch (funct3) { 2032 case 0b010: // fsw 2033 #if __riscv_flen == 64 2034 case 0b011: // fsd 2035 #endif 2036 return SignalContext::WRITE; 2037 default: 2038 return SignalContext::UNKNOWN; 2039 } 2040 #endif 2041 default: 2042 return SignalContext::UNKNOWN; 2043 } 2044 #else 2045 (void)ucontext; 2046 return UNKNOWN; // FIXME: Implement. 2047 #endif 2048 } 2049 2050 bool SignalContext::IsTrueFaultingAddress() const { 2051 auto si = static_cast<const siginfo_t *>(siginfo); 2052 // SIGSEGV signals without a true fault address have si_code set to 128. 2053 return si->si_signo == SIGSEGV && si->si_code != 128; 2054 } 2055 2056 void SignalContext::DumpAllRegisters(void *context) { 2057 // FIXME: Implement this. 2058 } 2059 2060 static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) { 2061 #if SANITIZER_NETBSD 2062 // This covers all NetBSD architectures 2063 ucontext_t *ucontext = (ucontext_t *)context; 2064 *pc = _UC_MACHINE_PC(ucontext); 2065 *bp = _UC_MACHINE_FP(ucontext); 2066 *sp = _UC_MACHINE_SP(ucontext); 2067 #elif defined(__arm__) 2068 ucontext_t *ucontext = (ucontext_t*)context; 2069 *pc = ucontext->uc_mcontext.arm_pc; 2070 *bp = ucontext->uc_mcontext.arm_fp; 2071 *sp = ucontext->uc_mcontext.arm_sp; 2072 #elif defined(__aarch64__) 2073 ucontext_t *ucontext = (ucontext_t*)context; 2074 *pc = ucontext->uc_mcontext.pc; 2075 *bp = ucontext->uc_mcontext.regs[29]; 2076 *sp = ucontext->uc_mcontext.sp; 2077 #elif defined(__hppa__) 2078 ucontext_t *ucontext = (ucontext_t*)context; 2079 *pc = ucontext->uc_mcontext.sc_iaoq[0]; 2080 /* GCC uses %r3 whenever a frame pointer is needed. */ 2081 *bp = ucontext->uc_mcontext.sc_gr[3]; 2082 *sp = ucontext->uc_mcontext.sc_gr[30]; 2083 #elif defined(__x86_64__) 2084 # if SANITIZER_FREEBSD 2085 ucontext_t *ucontext = (ucontext_t*)context; 2086 *pc = ucontext->uc_mcontext.mc_rip; 2087 *bp = ucontext->uc_mcontext.mc_rbp; 2088 *sp = ucontext->uc_mcontext.mc_rsp; 2089 #elif SANITIZER_OPENBSD 2090 sigcontext *ucontext = (sigcontext *)context; 2091 *pc = ucontext->sc_rip; 2092 *bp = ucontext->sc_rbp; 2093 *sp = ucontext->sc_rsp; 2094 # else 2095 ucontext_t *ucontext = (ucontext_t*)context; 2096 *pc = ucontext->uc_mcontext.gregs[REG_RIP]; 2097 *bp = ucontext->uc_mcontext.gregs[REG_RBP]; 2098 *sp = ucontext->uc_mcontext.gregs[REG_RSP]; 2099 # endif 2100 #elif defined(__i386__) 2101 # if SANITIZER_FREEBSD 2102 ucontext_t *ucontext = (ucontext_t*)context; 2103 *pc = ucontext->uc_mcontext.mc_eip; 2104 *bp = ucontext->uc_mcontext.mc_ebp; 2105 *sp = ucontext->uc_mcontext.mc_esp; 2106 #elif SANITIZER_OPENBSD 2107 sigcontext *ucontext = (sigcontext *)context; 2108 *pc = ucontext->sc_eip; 2109 *bp = ucontext->sc_ebp; 2110 *sp = ucontext->sc_esp; 2111 # else 2112 ucontext_t *ucontext = (ucontext_t*)context; 2113 # if SANITIZER_SOLARIS 2114 /* Use the numeric values: the symbolic ones are undefined by llvm 2115 include/llvm/Support/Solaris.h. */ 2116 # ifndef REG_EIP 2117 # define REG_EIP 14 // REG_PC 2118 # endif 2119 # ifndef REG_EBP 2120 # define REG_EBP 6 // REG_FP 2121 # endif 2122 # ifndef REG_UESP 2123 # define REG_UESP 17 // REG_SP 2124 # endif 2125 # endif 2126 *pc = ucontext->uc_mcontext.gregs[REG_EIP]; 2127 *bp = ucontext->uc_mcontext.gregs[REG_EBP]; 2128 *sp = ucontext->uc_mcontext.gregs[REG_UESP]; 2129 # endif 2130 #elif defined(__powerpc__) || defined(__powerpc64__) 2131 ucontext_t *ucontext = (ucontext_t*)context; 2132 *pc = ucontext->uc_mcontext.regs->nip; 2133 *sp = ucontext->uc_mcontext.regs->gpr[PT_R1]; 2134 // The powerpc{,64}-linux ABIs do not specify r31 as the frame 2135 // pointer, but GCC always uses r31 when we need a frame pointer. 2136 *bp = ucontext->uc_mcontext.regs->gpr[PT_R31]; 2137 #elif defined(__sparc__) 2138 #if defined(__arch64__) || defined(__sparcv9) 2139 #define STACK_BIAS 2047 2140 #else 2141 #define STACK_BIAS 0 2142 # endif 2143 # if SANITIZER_SOLARIS 2144 ucontext_t *ucontext = (ucontext_t *)context; 2145 *pc = ucontext->uc_mcontext.gregs[REG_PC]; 2146 *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS; 2147 #else 2148 // Historical BSDism here. 2149 struct sigcontext *scontext = (struct sigcontext *)context; 2150 #if defined(__arch64__) 2151 *pc = scontext->sigc_regs.tpc; 2152 *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS; 2153 #else 2154 *pc = scontext->si_regs.pc; 2155 *sp = scontext->si_regs.u_regs[14]; 2156 #endif 2157 # endif 2158 *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS; 2159 #elif defined(__mips__) 2160 ucontext_t *ucontext = (ucontext_t*)context; 2161 *pc = ucontext->uc_mcontext.pc; 2162 *bp = ucontext->uc_mcontext.gregs[30]; 2163 *sp = ucontext->uc_mcontext.gregs[29]; 2164 #elif defined(__s390__) 2165 ucontext_t *ucontext = (ucontext_t*)context; 2166 # if defined(__s390x__) 2167 *pc = ucontext->uc_mcontext.psw.addr; 2168 # else 2169 *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff; 2170 # endif 2171 *bp = ucontext->uc_mcontext.gregs[11]; 2172 *sp = ucontext->uc_mcontext.gregs[15]; 2173 #elif defined(__riscv) 2174 ucontext_t *ucontext = (ucontext_t*)context; 2175 *pc = ucontext->uc_mcontext.__gregs[REG_PC]; 2176 *bp = ucontext->uc_mcontext.__gregs[REG_S0]; 2177 *sp = ucontext->uc_mcontext.__gregs[REG_SP]; 2178 #else 2179 # error "Unsupported arch" 2180 #endif 2181 } 2182 2183 void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); } 2184 2185 void InitializePlatformEarly() { 2186 // Do nothing. 2187 } 2188 2189 void MaybeReexec() { 2190 // No need to re-exec on Linux. 2191 } 2192 2193 void CheckASLR() { 2194 #if SANITIZER_NETBSD 2195 int mib[3]; 2196 int paxflags; 2197 uptr len = sizeof(paxflags); 2198 2199 mib[0] = CTL_PROC; 2200 mib[1] = internal_getpid(); 2201 mib[2] = PROC_PID_PAXFLAGS; 2202 2203 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) { 2204 Printf("sysctl failed\n"); 2205 Die(); 2206 } 2207 2208 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) { 2209 Printf("This sanitizer is not compatible with enabled ASLR.\n" 2210 "To disable ASLR, please run \"paxctl +a %s\" and try again.\n", 2211 GetArgv()[0]); 2212 Die(); 2213 } 2214 #elif SANITIZER_PPC64V2 2215 // Disable ASLR for Linux PPC64LE. 2216 int old_personality = personality(0xffffffff); 2217 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) { 2218 VReport(1, "WARNING: Program is being run with address space layout " 2219 "randomization (ASLR) enabled which prevents the thread and " 2220 "memory sanitizers from working on powerpc64le.\n" 2221 "ASLR will be disabled and the program re-executed.\n"); 2222 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1); 2223 ReExec(); 2224 } 2225 #elif SANITIZER_FREEBSD 2226 int aslr_pie; 2227 uptr len = sizeof(aslr_pie); 2228 #if SANITIZER_WORDSIZE == 64 2229 if (UNLIKELY(internal_sysctlbyname("kern.elf64.aslr.pie_enable", 2230 &aslr_pie, &len, NULL, 0) == -1)) { 2231 // We're making things less 'dramatic' here since 2232 // the OID is not necessarily guaranteed to be here 2233 // just yet regarding FreeBSD release 2234 return; 2235 } 2236 2237 if (aslr_pie > 0) { 2238 Printf("This sanitizer is not compatible with enabled ASLR " 2239 "and binaries compiled with PIE\n"); 2240 Die(); 2241 } 2242 #endif 2243 // there might be 32 bits compat for 64 bits 2244 if (UNLIKELY(internal_sysctlbyname("kern.elf32.aslr.pie_enable", 2245 &aslr_pie, &len, NULL, 0) == -1)) { 2246 return; 2247 } 2248 2249 if (aslr_pie > 0) { 2250 Printf("This sanitizer is not compatible with enabled ASLR " 2251 "and binaries compiled with PIE\n"); 2252 Die(); 2253 } 2254 #else 2255 // Do nothing 2256 #endif 2257 } 2258 2259 void CheckMPROTECT() { 2260 #if SANITIZER_NETBSD 2261 int mib[3]; 2262 int paxflags; 2263 uptr len = sizeof(paxflags); 2264 2265 mib[0] = CTL_PROC; 2266 mib[1] = internal_getpid(); 2267 mib[2] = PROC_PID_PAXFLAGS; 2268 2269 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) { 2270 Printf("sysctl failed\n"); 2271 Die(); 2272 } 2273 2274 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) { 2275 Printf("This sanitizer is not compatible with enabled MPROTECT\n"); 2276 Die(); 2277 } 2278 #else 2279 // Do nothing 2280 #endif 2281 } 2282 2283 void PrintModuleMap() { } 2284 2285 void CheckNoDeepBind(const char *filename, int flag) { 2286 #ifdef RTLD_DEEPBIND 2287 if (flag & RTLD_DEEPBIND) { 2288 Report( 2289 "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag" 2290 " which is incompatible with sanitizer runtime " 2291 "(see https://github.com/google/sanitizers/issues/611 for details" 2292 "). If you want to run %s library under sanitizers please remove " 2293 "RTLD_DEEPBIND from dlopen flags.\n", 2294 filename, filename); 2295 Die(); 2296 } 2297 #endif 2298 } 2299 2300 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding, 2301 uptr *largest_gap_found, 2302 uptr *max_occupied_addr) { 2303 UNREACHABLE("FindAvailableMemoryRange is not available"); 2304 return 0; 2305 } 2306 2307 bool GetRandom(void *buffer, uptr length, bool blocking) { 2308 if (!buffer || !length || length > 256) 2309 return false; 2310 #if SANITIZER_USE_GETENTROPY 2311 uptr rnd = getentropy(buffer, length); 2312 int rverrno = 0; 2313 if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT) 2314 return false; 2315 else if (rnd == 0) 2316 return true; 2317 #endif // SANITIZER_USE_GETENTROPY 2318 2319 #if SANITIZER_USE_GETRANDOM 2320 static atomic_uint8_t skip_getrandom_syscall; 2321 if (!atomic_load_relaxed(&skip_getrandom_syscall)) { 2322 // Up to 256 bytes, getrandom will not be interrupted. 2323 uptr res = internal_syscall(SYSCALL(getrandom), buffer, length, 2324 blocking ? 0 : GRND_NONBLOCK); 2325 int rverrno = 0; 2326 if (internal_iserror(res, &rverrno) && rverrno == ENOSYS) 2327 atomic_store_relaxed(&skip_getrandom_syscall, 1); 2328 else if (res == length) 2329 return true; 2330 } 2331 #endif // SANITIZER_USE_GETRANDOM 2332 // Up to 256 bytes, a read off /dev/urandom will not be interrupted. 2333 // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom. 2334 uptr fd = internal_open("/dev/urandom", O_RDONLY); 2335 if (internal_iserror(fd)) 2336 return false; 2337 uptr res = internal_read(fd, buffer, length); 2338 if (internal_iserror(res)) 2339 return false; 2340 internal_close(fd); 2341 return true; 2342 } 2343 2344 } // namespace __sanitizer 2345 2346 #endif 2347